Field of the Invention
Applicants' invention relates to a device for magnetic anti-tampering system. More particularly, it relates to magnetically paired keys and locks that use lever tumblers.
Background Information
There are many keys for many different types of locks. One type of lock and key commonly used in prisons and correctional facilities is the paracentric. Paracentric literally means to deviate from circularity, or changing the distance from a center. A paracentric key is distinguishable by the heavily contoured shape of its blade, which protrudes past the center vertical line of the keyway in the cylinder. Locks with paracentric keyways offer a higher level of protection against picking since they prevent direct access to the pins by traditional picking tools. A paracentric lock has a keyway with one or more wards on each side projecting beyond the vertical center line of the keyway. Instead of the wards on the outer face of the lock simply protruding into the shape of the key along the spine, the wards protrude into the shape of the key along the entire width of the key, including along the length of the teeth. The shape and wards of the paracentric lock and key are designed to hinder picking. This is the reason that person could locks and keys are often used in jails. However, even the paracentric lock and keys are not completely immune to picking by motivated individuals such as inmates.
A pin tumbler lock is a lock mechanism that uses pins of varying lengths to prevent the lock from opening without the correct key. Pin tumblers are most commonly employed in cylinder locks, but may also be found in other types of locks as well.
Pin tumbler locks are made up of a Bible which sits around a cylindrical plug. Unimpeded, the plug will rotate inside the Bible. The Bible of the lock contains the springs and the driver pins. The driver pins sit between the Bible and the plug of the lock. The plug is the portion of the lock that contains the keyway and will turn when the correct key is inserted. Below the driver pins are the key pins. The key pins will actually touch the key when it is inserted. The driver pins and the key pins are in contact and a thought one another but are not connected. All of the pins slide within a cylinder with the springs urging the pins down. The driver pins and springs are all the same length. In contrast, each of the key pins has a unique length that corresponds to the unique cuts (teeth) in the key. When no key is in the keyway, the springs urge the driver pins past the junction of the Bible and plug, thus the driver pins block rotation of the plug. If an incorrect key is inserted into the lock, then the lock teeth will either be too short or too tall. If a key tooth is too big, then the driver pin/lock pin combination is moved against the spring such that the lock pin extends beyond the junction of the Bible and plug and the lock pin blocks rotation of the plug. If a key tooth is too small, then like when there is no key at all, the spring urges the lock pin past the junction of the Bible and plug again blocking rotation of the plug. Of the Bible and plug is called the sheer line. When the correct key is inserted into the lock, the key pins are raised by the teeth such that the top of the key pins and the bottom of the driver pins sit at the sheer line. This allows the plug to rotate and disengage the lock.
In contrast to the pin tumblers, a lever tumbler lock is a type of lock that uses a set of levers (instead of pins) to prevent the bolt from moving in the lock. In the simplest of these, lifting the tumbler above a certain height will allow the bolt to slide past. In a double acting lever lock a slot is cut in the lever so that the lever must be lifted to a certain height but not too far in order for the bolt to be allowed to move within the lock. The number of levers may vary, and may be increased in order to provide correspondingly increased levels of security.
In the past, magnetic keys have been used with pin tumbler type locks. A magnetic-coded lock uses pins in combination with magnets to prevent unlocking with non-matching keys by teething and magnetic polarity. Magnetic locks/keys use paired magnets with opposing poles inside the key and plug. When a correctly matched key is inserted into the lock, not only are all the mechanical pins pushed into the correct positions, the magnetic pins are also driven to the appropriate level by the magnetic force inside the key. Magnetic-coded locks offer heightened security because in order to unlock a lock not only must the key teething fit with the pins, the magnetic pin locations and poles of the lock and key must correspond. The correct fitting position can be found by feeling the effect of the magnetic force, or by aligning with the markings. When the magnetic key is placed on a magnetic lock, the lock magnets online the magnetic catches arranged in a freely rotatable manner in relation to the key magnets such that the opposite poles oppose each other. Further, the lock magnets are pulled by the key magnets into locked positions. This occurs because the attractive force acting between the lock magnets and the key magnets is slightly greater in the online edition and the attractive force acting between the lock. If there is no magnetic key or respectively corresponding external magnetic force, the magnetic attraction of the key magnets combined so that the magnetic catches independently pull themselves into the locked position. This is in addition to the spring mechanisms of the pin tumbler locks.